http://www.daftar.org/Far/contact_far.asp The best thing you can do is to go there ( if possible) and talk to Mr. Rokhvand . He is the best person you can ask questions. Or call the office . Guideline change , they used to ask for invitation and or sponsor by someone from Iran. Plus a good clear reason why you going there . Contact them for most updated guidelines and procedures.
You need to apply for a visa. The Interest Section does issue visas. More information is available on http://www.daftar.org
Thanks! Your answer is awaiting moderation.